package summer_vacation.cullen.one10;

import java.util.Scanner;

/**
 * Created by Cullen on 2015/8/4.
 */
public class N23 {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        System.out.println("请输入成绩：");
        int a=input.nextInt();
        for(;a>100 || a<0;){
            System.out.println("成绩有误，请重新输入：");
            a=input.nextInt();
        }
        if (a>=90){
            System.out.println("A");
        }else if (a>=80){
            System.out.println("B");
        }else if (a>=70){
            System.out.println("C");
        }else if (a>=60){
            System.out.println("D");
        }else
            System.out.println("E");
    }
}
